1. Field of the Invention
The present invention generally relates to an image-processing device, and more particularly, to an image-processing device detecting a character in image data so as to apply a proper image processing thereto, an image-reading device comprising the image-processing device, an image-forming device comprising the image-processing device, and a color-copying device comprising the image-processing device.
2. Description of the Related Art
The invention disclosed in Japanese Laid-Open Patent Application No. 6-152945 is publicly known as a technology related to the above-referenced image-processing device. In this invention, a white ground is detected so that a character field with a small line width and a character field with a large line width are separately processed.
The invention disclosed in Japanese Laid-Open Patent Application No. 10-108012 is also publicly known. In this invention, a white ground is detected so that a field surrounded by the white ground is processed as a picture field.
However, switching the image processing according to a line width yields an unnatural image at a line-width boundary at which the image processing is switched. For example, reading and printing a character having a low density of 0.7–1.0 results in an edge of the character being emphasized, and an outline of the character being fringed, which makes the character hard to see.